慢性热应激对猪肠道CD3^＋T细胞表达的影响

以猪肠道CD3＋T细胞为研究对象,旨在观察慢性热应激对猪肠道黏膜免疫功能的影响。12头小型猪随机平均分成热应激组和常温对照组两组。人工气候室内,热应激组模拟夏季炎热气候,气温从26～39℃24h循环变温,在39℃时维持4h;常温对照组在24℃下饲养。试验持续10d,热应激10d后39℃高温持续期结束剖杀试验猪,取其十二指肠中段、空肠及回肠中段进行固定、石蜡切片、免疫组织化学染色,观察十二指肠、空肠及回肠中CD3＋T细胞数量的变化。结果显示：实验猪十二指肠黏膜上皮层、固有层及十二指肠肠腺均呈CD3强阳性,与对照组相比,CD3阳性面积系数显著上升（P〈0.05）;空肠和回肠黏膜上皮层的CD3阳性细胞数量也显著增加（P〈0.05）,而固有层中的CD3阳性细胞数量则无明显变化,增加的幅度小于十二指肠。慢性热应激中实验猪肠道结构严重受损,消化吸收功能严重下降,而肠道CD3＋T细胞的增多,可能是机体肠道黏膜免疫功能的一种代偿性增强反应。

Effect of Chronic Heat Stress on CD3+T Cells in Pigs' Intestines

In this paper,intestinal CD3+ T cells were studied to observe the chronic heat stress on the pig intestinal mucosa immune function.Twelve healthy three-month-old pigs were divided into two groups at random,heat stress group and control group.The two groups were put into different AGCs,one of which simulated high temperature in summer(the temperature changed from 26℃ to 39℃ and lasted four hours when 39℃),the other always keep 24℃.The experiment lasted ten days.After tendays,heat stress duration of 39 ℃ high temperature test pigs sacrificed at the end,whichever is the middle of the duodenum,jejunum and middle ileum were fixed,paraffin section,immunohistochemistry staining of duodenum,Jejunum and ileum in the number of CD3+ T cells changes.The results showed that: experimental pig duodenal mucosa epithelium,stroma,and duodenal crypt showed strong positive CD3,compared with the control group,CD3-positive area index increased significantly(P <0.05);jejunum and ileum mucosa CD3-positive cells on the cortex were also significantly increased the number(P <0.05),while the lamina propria in the number of CD3 positive cells did not change significantly,the rate of increase is less than the duodenum.Heat stress in pigs with chronic intestinal structure is seriously damaged,a serious decline in digestion and absorption,and intestinal CD3 + T cells increased,possibly intestinal mucosal immune function in the body a compensatory enhanced response.